PURPOSE: To predict the generation of a crack by detecting a minute sound generated from a centrifugal reinforced concrete pipe during loading at the time of deciding a cracking load in the case of the external pressure strength test of the centrifugal reinforced concrete pipe.
CONSTITUTION: In the case of deciding a cracking load at the time of the external pressure strength test of a centrifugal reinforced concrete pipe, by detecting a minute sound generated from the centrifugal reinforced concrete pipe in the course of loading, it becomes an auxiliary means for deciding the cracking load. Also, an acoustic detecting sensor is installed on the surface of the pipe, and with respect to an obtained acoustic signal, by analogizing or digitizing a minute acoustic output generated from the pipe by an acoustic signal processor, and deriving the maximum value of a generated acoustic output per unit time, the generation of a crack of 0.05mm width is predicted.
TSUJI MASAYUKI
NISHIOKA KOICHIRO
FUJIWARA HIROKI
